Visions and visioning in CHI

There are many visions that touch on the future of human computer interaction from a trans-human future to a post-technological UI. However visions related to the progress of technology are not new. Creative and insightful visionaries from Denis Diderot to Vannevar Bush have been postulating visions of possible futures or technology for centuries. Some idealised views end up discredited with advances in knowledge, while others now appear remarkably prescient. The question is, do visions and the process of creating them have a place in CHI, or are they simply flights of fancy?